import type {
  Map as MapLibreMap,
  MapMouseEvent,
  Marker as MapLibreMarker,
} from 'maplibre-gl';

/** Subset of maplibre-gl used by the web MapPinSelector. */
export interface MapRuntime {
  Map: new (
    options: ConstructorParameters<typeof import('maplibre-gl').Map>[0]
  ) => MapLibreMap;
  Marker: new (
    options?: ConstructorParameters<typeof import('maplibre-gl').Marker>[0]
  ) => MapLibreMarker;
  AttributionControl?: new (
    options?: ConstructorParameters<
      NonNullable<typeof import('maplibre-gl').AttributionControl>
    >[0]
  ) => import('maplibre-gl').AttributionControl;
  NavigationControl?: new (
    options?: ConstructorParameters<
      NonNullable<typeof import('maplibre-gl').NavigationControl>
    >[0]
  ) => import('maplibre-gl').NavigationControl;
}

export type { MapLibreMap, MapLibreMarker, MapMouseEvent };

/**
 * How the host provides MapLibre GL JS.
 * - `bundled`: import from `maplibre-gl` (default — Next.js, Vite apps with the peer installed)
 * - `external`: read from `window.maplibregl` (CDN script loaded before the widget, e.g. Shopify)
 */
export type MapEmbedMode = 'bundled' | 'external';

/** Carto Positron — default basemap for standard web embeds. */
export const DEFAULT_MAP_STYLE_URL =
  'https://basemaps.cartocdn.com/gl/positron-gl-style/style.json';

/** OpenFreeMap Positron — free, no API key (used when Carto credentials are unavailable). */
export const OPENFREEMAP_POSITRON_STYLE_URL =
  'https://tiles.openfreemap.org/styles/positron';

const MAPLIBRE_WAIT_MS = 8_000;
const MAPLIBRE_RETRY_MS = 100;

declare global {
  interface Window {
    maplibregl?: MapRuntime;
  }
}

export function getExternalMapRuntime(): MapRuntime | null {
  if (typeof window === 'undefined') return null;
  const maplibre = window.maplibregl;
  if (
    !maplibre ||
    typeof maplibre.Map !== 'function' ||
    typeof maplibre.Marker !== 'function'
  ) {
    return null;
  }
  return maplibre;
}

/**
 * Poll `window.maplibregl` until available or timeout (for async CDN loads).
 * Returns a cancel function for useEffect cleanup.
 */
export function waitForExternalMapRuntime(
  onReady: (runtime: MapRuntime) => void,
  onUnavailable: () => void,
  waitMs: number = MAPLIBRE_WAIT_MS,
  retryMs: number = MAPLIBRE_RETRY_MS
): () => void {
  const startedAt = Date.now();
  let retryTimer: number | null = null;
  let cancelled = false;

  const tryGet = () => {
    if (cancelled) return;
    const runtime = getExternalMapRuntime();
    if (runtime) {
      onReady(runtime);
      return;
    }
    if (Date.now() - startedAt >= waitMs) {
      onUnavailable();
      return;
    }
    retryTimer = window.setTimeout(tryGet, retryMs);
  };

  tryGet();

  return () => {
    cancelled = true;
    if (retryTimer !== null) window.clearTimeout(retryTimer);
  };
}